From North Korea to its Muslim west and beyond, Beijing has its hands full.

When North Korea tested its nuclear weapons last year, the people of Yanji, China, felt an earthquake. When civil wars tore apart a section of northeast Myanmar, small towns in southern Yunnan flooded with tens of thousands of frightened Burmese refugees. When demonstrations by China’s Muslim Uighurs erupted into deadly riots that underscored the depth of ethnic tensions, new questions arose about China’s policies of cultural assimilation and controls on the practice of Islam and other religions. In short, China’s most delicate and dicey challenges are often seen most dramatically on its borders.